Download KB977206 to Run Windows Virtual PC (XP Mode or VM) With No Hardware Virtualization

One of the original system requirement (part of Windows 7 system requirements) for Windows Virtual PC (and hence Windows XP Mode) is that CPU must support hardware-assisted virtualization (HAV) and has the feature turned on or enabled in BIOS. The Windows Virtual PC (VPC) designed specifically for Windows 7, take advantage of HAV support on processor to improve the performance of virtualization technology (VT) when the virtual machines are powered on.
Some computer system with low-end or mid-range Intel and AMD CPU processor which does not support hardware-assisted virtualization (such as Intel VT-x, VT-d or AMD-V). Even if HAV is supported, some PC manufacturers and vendors have the function disabled, turned off and locked in BIOS level (Tip: How to check and verify hardware virtualization support on processor). As the result, user cannot start, configure or run any virtual machine including Windows XP Mode in Windows Virtual PC. One of the following error messages will be displayed instead:

This error message indicates that the processor does not support the HAV feature.

Windows Virtual PC cannot start because this computer does not support hardware-assisted virtualization

This error message is displayed when user tries to start or configure a virtual machine that is not running Windows XP Mode. This error message indicates that the processor does not support the HAV feature.

To make virtualization more accessible to many more PCs for small and midsize businesses wanting to migrate to Windows 7 Professional, Ultimate and Enterprise, while still running Windows XP-based productivity applications, Microsoft decides to remove the hardware virtualization technology prerequisite requirement in order to run Windows Virtual PC. It means that any PC with Windows 7, and with the hack for Windows 7 Home Premium, Home Basic and Starter to install Windows Virtual PC and Windows XP Mode), everybody can install and run Windows Virtual PC to power up any (virtual machine) on any computer and system.

To enable Windows Virtual PC and Windows XP Mode on computer without hardware virtualization support, Microsoft releases KB977206 Update for Windows 7, which removes the prerequisites required to run Windows Virtual PC and XP mode. The prerequisites include a processor which supports hardware assisted virtualization (HAV) which is also enabled in the BIOS.

Note that if your current system already installed with and can run Windows Virtual PC and Windows XP Mode, the update is not required and not necessary. Windows Virtual PC will still take advantage of hardware virtualization support if it’s available. In fact, Microsoft says that while customers can start using Windows Virtual PC to run Windows XP Mode or create virtual machine running Windows Vista or Windows 7 without having to worry about hardware virtualization, HAV is still recommended for later case as the non-HAV is only supported and tuned for XP Mode.